Brake gauge



y 1938. H. B. BARRETT 2,124,603

BRAKE GAUGE Filed July 25, 1936 I N VEN 7-072 Halg .5. .B rrefi.

Patented July 26, 1938 UNITED STATES PATENT OFFICE BRAKE GAUGE Harry B. Barrett, St. Louis, Mo

Application July 25, 1936, Serial No. 92,532

17 Claims. (Cl. 33-180) This invention relates generally to gauging tools and, more particularly, to a certain new and useful improvement in tools especially, though not exclusively, adapted for the precision gauging and setting of automobile brakeshoes and the like.

Automobile brakes usually comprise cylindrical drums rigidly fixed to the wheels and expandible and contractible shoes suitably cold'operably mounted pivotally with respect to the drums for applying braking pressure to the drums and hence also to the wheels. For applying such pressure, the shoes arelined with-suitable fabric or other friction material, such as asbestos strips,

and for obtaining the maximum of braking effi- V ciency, it is essential that the shoes not only be accurately positioned with proper drum-clearance both at toe and heel when contracted, but also that the respective drum-engaging faces of the linings have precise and accurate curvature relatively to the cylindrical faces of the respective drums.

My present invention has hencefor its chief object the provision of a portable tool so constructed foraccurately setting the liningequipped shoes throughout their peripheralsurface to the desired drum-clearance when contracted for uniform effective braking-engagement when expanded with their surrounding drum.

My invention has for a further object the provision of a tool of the type and for the purpose stated, which is simple, sturdy, and durable in structure, which may be manipulated readily,

conveniently, and with facility in brake-shoe calibrating and setting operations, which may be operably mounted upon any spindle, front or rear and whether of tapering or other contour or formation, and which is efficient in the performance of its intended functions.

And with the above and other objects. in view, my invention resides in the novel features. of form, construction, arrangement, and combinain the claims.

In the accompanying drawing,

Figure 1 illustrates a brake-gauging tool of my invention in spindle-mounted position for a brake-shoe checking and setting operation;

Figure 2 is a side elevation of the tool in operable position as in Figure 1;

Figures 3 and 4 are enlarged fragmental elevational and sectional views, respectively, of the spindle-engaging members of the tool; and

tion of parts presently described and pointed out Figure 5 is a fragmentary side elevation of the tool in brake-drum measuring position.

Referring now more in detail andby reference characters to the drawing, which illustrates a preferred embodiment of the tool, A designates 5 a standard automobile-wheel axle or spindle, and forming part of what may be described as the axle-assembly, is disk-shaped member B, suitably adjustably pivoted at an end upon which, as at I, are opposed or companion brake-shoes 10 C, in the present instance oflthe internal expanding hydraulic type, pivotally connected at their other end, as. at 2, to, and shiftable. by, piston-rods 3 working in a cylinder l, Suitably fixed on the peripheral faces of the shoes C, 15"

are suitable lining-strips 5 for "frictional wheelbraking engagement, when the shoes C are expanded, with theinner circumferential face of a surroundingdrum E rigidly fixed about the hub of, and on the face of, the usual wheelgnot 20 shown, all as will be well understood. .x

D designates the brake-gauging tool, which includes a main or body-portion inthe form preferably of a suitably elongated yoke 6 provided longitudinally upon a side face with a 25 position relatively to the yoke 6, is a securing 5 7 device H, and lengthwise slidable through the block 8 and disposed in parallelism,v and having a strap-connection, as at l2, with, the staff 9, is a suitably elongated bar I3 provided at its lower end with what may be described as companion 40 horns I4jfor en'dwise engagement with the particular spindle A, as presentlymorefully appears. Also slidable for adjustment on, and equipped with a set-screw or the like I5 for retaining engagement with, th e staff 9, is a second block I6, 45 through which an arm'in the form preferablyof a suitably elongated bar I! is adjustably slidable at right angles to the staff 9,. the. arm ll 7 being preferably disposed for movement endwise through a plane longitudinally projected 50 from the bar or stafi-extension l3, and the block l6 being also equipped with a set-screw or the, like I8 for engaging the arm I! for retaining the same in selected or adjusted position. v

The am i 1- isprovided with a" contacting sur- 55 upside-down, so that the contacting surface ll faces upwardly. The contacting surface ll may then be brought to bear against the brake drum E to test the concentricity thereof'and, if necessary, obtain a proper setting of the block [6.

The arm il may then be withdrawn fromthe block, leaving all settings of the instrument constant. The arm I! is then reversed, so that the contact surface El faces downwardly, and in this position the arm il may be used to gaugethe surface of the brake lining, so that the brakeshoes will be gauged by the same measurement as obtained from the brake-drum, assuring an accurate setting'of the shoes in relation to the brake-drum.

" surface I is atthe axial middle of the arm ll,

"ing is adjusted against this contactsurface ll,

the surface will lie in exactly the same position with respect to its radial distance from the center of the brake-drum in either the upward or downward facing position, so that when the brake linit will fit properly within the brake drum upon operation of the brake assembly. v v

Projecting laterally from an end, and forming substantially a part, of: yoke 6, is a first arm or' jaw is Igrooved or cut-away upon its inner face and thereby provided with opposed faces, as at 20, for engagement with the spindle A; and projecting laterally from the oppositefend, and also forming substantially a part, of yoke 6 in opposed relation toothe jaw 19, is a second armor jaw 21, adjustably threaded through which for spindle-engagement, is a suitably elongated screw-memberZZ. I

For purposes presently side face, as best seen in Figure 4, and mounted for threaded adjustment in, and transversely of, such enlarged portion'of jaw I9, is a screw-member 23 having'a manipulating head 24. Disposed upon opposite sides ofothe's'crew-member 23- for engagement by its head 24, and looselyshiftable through'the jaw 59 for impinging engagement upon corresponding actuation'of the head324 with an interposed spindle in opposition to'the screwmember 22, are pins25. o

So constructed, in use and operation, the block [6 is first shifted along, and selectively positioned on, staff 9 to transfer and indicate thereon sub-' stantially the exact diametrical dimension of the particular drum with which the shoes C are to function. The tool is then disposed with its yoke 6 in embracing position about, and its jaw l9 engaged with, the particular interposed spindle A, screw-member 22 being then opposingly threaded into binding engagement with, and the tool thereby firmly secured for rotative movement about, the embraced or interposed spindle A. The block 8 is thereupon shifted and then secured in its slide-way l to position the staff-extension l3 radially with respect to, and for endwiseengagement atoits horns M with, the interposed spindle A, with the result that the arm I! is precisely radially centered concentrically with respect to the axis of the spindle A5 The arm It will be notedthat, sincethe" appearing, the arm or jaw I9 is enlarged at or adjacent its one or outer I! may then, of course, be suitably shifted and secured in block I6 for engagement with the peripheral face of the lined shoes C for thus readily,

conveniently, and with facility checking and enabling, on rotative movement of the tool about the spindle A, accurate and precise'setting of the shoes C throughout their circumferential face and with the desired toe and heel clearance for efficient peripheral braking engagement with their co-operable surrounding drum.

As will be observed, the spindle A is substantially of uniform diametrical dimension. In the event the interposed spindle is of tapering type, -as,for instance, spindle A, the jaw l9 will engage the spindle A at or adjacent the so-called inner side-margin of the jaw, as shown. The

"- screw-memberifi is turned and pins 25 are shifted thereby into endwise engagement with the spindle A at points spaced from the point of engagement therewith of the jaw-faces 20. Thus the jaw 19, in opposition to screw-member 22, is

evenly engaged with the spindle A, and the tool thereby likewise retained upon, and for rotative movement about or with, the tapering spindle A;

The tool fulfills in every respect the objects stated, the adjustable jaw-members 22, 23-, enabling the facile engagement of the tool with various types and sizes of wheel-spindles, and it is to be understood that changes and modifica tions in the form, construction, arrangement, and combination of the several parts of the tool may be made and substituted forthoseherein shown and described withoutdeparting from'the nature and principle of my invention- 7 Having thus described my invention, what I claim and desire to secure by Letters Patent is, l. A; brake-gauge including a yoke for rotative engagement with an interposed spindle, a scaleshaft, a shoe-engaging armon the shaft, and

shaft-supporting means mounted for shiftable movement on'the yoke for radially centering the arm concentrically with respect to the axis of the engaged spindle.

2. A brake-gauge including a yoke for jrotative engagement with an interposed spindle, a scaleshaft disposed ata right, angle to the yoke, a

shoe-engaging arm on the shaft, and shaft-supporting means mounted for shiftable movement on the yoke for shifting the shaft relatively to rthe engaged spindlefor radially centering the arm, concentrically withrespect to the axis of said spindle,

'3. A brake-gaugefincl'udinga yoke for rotative engagement with an interposed spindle, a block adjustably'shiftable on the yoke relatively to; the engaged spindle,'a scale-staff carried by the block at right angles to the yoke, an arm mounted on,

and disposed at rightangles to, the staff for 'shoeengagement, and spindle-engaging'means carried by the block for locating the block relatively to the spindle for radially centering the arm concentrically with respect to. the axis of the spindle. a

4; 'A brake-gauge including a yoke for rotative V engagement with an interposed spindle, a block adjustably shiftable on the yoke relatively to the engaged spindle, a scale-staff carried by the block at right angles to the yoke, an arm mounted on,

and disposedat right angles to, the staff for shoe-engagement, and a bar carried by said block and shiftable in parallel alignment withthe staff for engagement with the spindle for locatingthe block relatively to the spindle for radially centering the arm concentrically with respect to the axis of the spindle. 3 A i 7 7 5. A brake-gauge including a longitudinally:

slotted yoke having spaced arms for embracing:

engagement with an.interposed spindle, ablock adjustably shiftable in the slot of the yokelirelatively to the spindle, a scalestaff carriedby the block at. right angles to the spindle, a shoe-engaging arm mounted for adjustment on, and dis-: posed at right angles to, the staff, and a bar carried by the block and lengthwise-disposed for adjustment in parallelism with the stafi for endwise engagement with the spindle for locating the block relatively to the yoke and spindle for radially centering the arm concentrically with respect to the axis of the spindle.

6. A brake-gauge including a longitudinally slotted yoke having spaced arms for embracing an interposed spindle, one of said arms having an inner face for rotative spindle-engagement, a screw-member having threaded engagement with the other arm for endwise rotative impinging engagement with said spindle in opposed relation to the first arm, a block adjustably shiftable in the slot of the yoke relatively to the spindle, a scale-staff carried by the block at right angles to the spindle, a shoe-engaging arm mounted for adjustment on, and disposed at right angles to, the staff, and a bar carried by the block and'lengthwise disposed for adjustment in parallelism with the staff for endwise engagement with the spindle for locating the block relatively to the yoke and spindle for radially centering the arm concentrically with respect to the axis of the spindle.

'7. A brake-gauge including a longitudinally slotted yoke having spaced arms for embracing an interposed spindle, members carried by, and

shiftable with respect to, the arms for endwise rotative impinging engagement in opposed relation with said spindle, a block adjustably shiftable in the slot of the yoke relatively to the spindle, a scale-staff carried by the block at right angles to the spindle, a shoe-engaging arm mounted for adjustment on, and disposed at right angles to, the staff, and a bar carried by the block and lengthwise disposed for adjustment in parallelism with the staff for endwise engagement with the spindle for locating the block relatively to the yoke and spindle for radially centering the arm concentrically with respect to the axis of the spindle.

8. In a brake-gauge, a yoke including a jaw for disposition about a tapering spindle, the jaw having an inner face for marginal engagement with the spindle, pins shiftable on and transversely of the jaw for endwise engaging the spindle at a point spaced from the point of engagement therewith of the face of the jaw, and a headed member adjustable on the jaw for shifting the pins for spindle-engagement.

9. A brake-gauge comprising a yoke having opposed jaws for embracingly engaging an axle spindle, one of said jaws having a spindle-contacting portion rigidly mounted thereon, and a spindle-engaging. member shiftably mounted thereon and spaced from the spindle-contacting portion thereof, for adjustable movement radially with respect to the spindle, and means operably mounted on the spindle for shifting the spindleengaging member to any desired position of adjustment.

10. A device of the character described comprising a yoke having opposed jaws for disposition about a spindle, one of said jaws being provided with a spindle-contacting portion, a pair of longitudinally shiftable spindle-engaging pins mounted irifsaid j aw: iforadjustable movement with? respect. to the spindle, means operably mounted on said jaw for shifting said pins to any predetermined position of adjustment, and a clampingiscrew operably mounted in the other jaw for engagement with the spindle. N

',1'1.-A device 'of the character described com prising a yoke. having opposed jaws for dispositionabout a spindle, one of said jaws being provided with a spindle-contacting portion, a-pair of longitudinally shiftable spindle-engaging pins mounted in said jaw for adjustable movement with respect to the spindle, a screw operably mounted on said jaw intermediate the pins and having a shoulder for endwise abutting engagement therewith for shifting said pins to any predetermined position of adjustment, and a clamping screw operably mounted in the other jaw for engagement with the spindle.

12. A device of the character described comprising a yoke having opposed jaws for disposition about a spindle, one of said jaws having a V-shaped channel formed transversely across its inwardly presented face parallel with the axial line of the spindle for embracing engagement at its one end with the spindle, a pair of longitudinally shiftable spindle-engaging pins mounted in said jaw adjacent its other end and positioned symmetrically on either side of the center-line of the channel, means operably mounted on said jaw for shifting said pins to any predetermined position of adjustment, and a clamping screw operably mounted in the other jaw for engagement with the spindle.

13. A brake-gauge including a yoke for engagement with an interposed spindle at diametrally opposed points on a selected diameter of said spindle, a movable member mounted on the yoke for shiftable movement along a line parallel to the selected diameter of the spindle, a shaft mounted rigidly on the movable member at right angles to the line of movement thereof, centering means shiftably mounted on themovable member and being engageable with the spindle for positioning the shaft in predetermined relation to the spindle, and brake-shoe engaging means shiftably mounted on the shaft.

14. In a brake-gauge, a yoke including a jaw for disposition around a tapering spindle for engagement therewith substantially along a selected diameter of the spindle, said jaw having an inner face for marginal engagement with the spindle, means adjustably mounted on the jaw for engaging the spindle at a point laterally spaced from the point of engagement between the spindle and said inner face of the jaw, and brake-shoe engaging means mounted on the yoke and operably disposed substantially within a plane at right angles to a plane passing through the axis of the spindle and the selected diameter.

15. A brake-gauge including a yoke having means for engagement with an interposed tapering spindle at substantially diametrally opposed points on a selected diameter of the spindle, a support operably mounted on the yoke at right angles to said selected diameter, and means operably mounted on and extending outwardly from said support for contacting engagement with the surface of a brake-shoe.

16. A brake-gauge including a yoke having means for engagement with an interposed tapering spindle at substantially diametrally opposed points on a selected diameter of the spindle, a shaft operably mounted on and extending outwardly from the yoke at right angles to said semeans for engagement with an interposed tapering spindle at substantially diametrally opposed points on a selected diameter of the spindle, a shaft operably mounted on the yoke a't right angles tosaid selected diameter, brake-shoe engaging means operatively mounted on, and extending outwardly at right angles to, said shaft, and means adjustably mounted on the yoke and engageable with the spindle whereby to swing the yoke angularly with respect to the spindle'axis and accordingly swing the brake-shoe engaging means into alignment with the spindle axis while 7 maintaining said brake-shoe engaging means in' a plane parallel to said spindle axis.

' HARRY ,B. BARRETT. 

